During a media event Thursday evening, T-Mobile's Mike Sievert and SpaceX's Elon Musk announced a new partnership that's intended to connect the mobile phones that T-Mobile currently sells to a new batch of SpaceX's Starlink satellites. The result, according to the companies, will be the elimination of all cellular dead zones around the US.

"I think what we're doing here is profound," Musk said during the event. "It will save lives."

"It's a lot like putting a cellular tower in the sky," Sievert said, adding that the "vast majority" of T-Mobile's existing phones would be supported by the service. Meaning, customers will not need to purchase new phones in order to connect them to Starlink's second-generation satellites.

Moreover, Sievert said that T-Mobile expects to offer the service for no additional charge on its more expensive plans. For customers on its cheaper plans, he said they may need to pay an additional monthly charge in order to be able to access satellite coverage.

The executives said they hope to begin testing the technology in late 2023. They did not say when it might launch commercially.

Getting into space

However, the executives cautioned that they're not announcing a new service or product, but rather their intention to work together to develop a service that would connect existing mobile phones to Starlink's second-generation satellites. Meaning, there remain a number of obstacles that the companies must overcome in order to actually begin offering such a service.

First, and perhaps most importantly, SpaceX will need to receive regulatory approval to launch its bigger Gen 2 satellites for its Starlink Internet service. According to CNet, Starlink's Gen 2 satellites are much, much bigger than the satellites it's currently operating (Starlink has so far launched 2,500 of its first-generation satellites into orbit). Starlink's Gen 2 satellites are 22 feet long and weigh 2,755 pounds, whereas its existing, first-generation satellites weigh 573 pounds.

That also means Starlink will need a bigger rocket to get its heavier Gen 2 satellites into orbit. SpaceX is hoping to use its planned Starship heavy-lift reusable rocket for such launches. SpaceX's Starship is the tallest and most powerful launch vehicle ever built, but it is still in the testing phase.

Interestingly, Musk said that, if SpaceX cannot get Starship up and running by next year, the company might consider building a smaller version of its Gen 2 satellites that could be launched with existing SpaceX rockets.

The reason Starlink needs bigger satellites is because they must be able to connect to hand-sized mobile phones hundreds of miles away, on the surface of the Earth. Starlink's current, first-generation satellites can only connect to the company's Starlink receivers on Earth, which are about the size of a pizza box.

Another challenge: Analyst Tim Farrar with TMF Associates noted that the FCC has not yet officially approved any satellite-to-phone communications in the US, by AST SpaceMobile, Lynk or any other company.

Think texting, not surfing

Musk said that Starlink only needs to launch and operate a few Gen 2 satellites in order to begin connecting to T-Mobile's mobile phones, via the operator's PCS spectrum. However, users likely won't be able to browse the Internet or make calls, at least initially. Musk said that Starlink's Gen 2 satellites will be able to offer around 2-4 Mbit/s of service inside a given coverage area, and that capacity will need to be shared by all the T-Mobile customers in that satellite service area. Initially, that means only text messaging will be supported because it doesn't require much data.

Sievert explained that T-Mobile hopes to support a variety of messaging services, from WhatsApp to Apple's iMessage. However, he said the company will need to be able to identify those messages inside of other web traffic. That will require messaging providers to work directly with T-Mobile. He said the operator expects to introduce a program in which messaging providers can work with the operator to ensure their services are covered under its satellite-based offering. T-Mobile previously conducted those kinds of programs when it began offering free streaming music, and later free streaming video.

Musk and Sievert said initial services will likely be intended for emergency situations, allowing backcountry travelers to text for help if they have problems, for example.

"It's not a substitute for ground cell stations," Musk said. "This is really meant to provide basic coverage."

Also, Musk said Starlink hopes to offer the service in other countries with other mobile network operators. "We do want to work with other partners in other parts of the world," he said.

Figure 1: A SpaceX Starlink terminal installed in Ukraine.
(Source: Abaca Press/Alamy Stock Photo)

Another satellite-to-phone player

T-Mobile and SpaceX are by no means the first companies to discuss the possibility of connecting existing mobile phones to satellites. Startup Lynk has already tested a similar service with its own satellites, and expects to begin offering commercial services by the end of this year. The company has already inked deals with global operators including Aliv in the Bahamas and Telecel Centrafrique in the Central African Republic.

AST SpaceMobile, which recently became a public company, is also working to launch its own satellites for a phone-to-satellite service. The company has deals with the likes of Rakuten, AT&T and Vodafone.

And satellite startup Omnispace, which owns 2GHz spectrum licenses, recently said it would work with Philippine mobile network operator Smart Communications for satellite-to-phone services.

Beyond that, satellite operator Globalstar has been widely rumored to be involved in some kind of agreement with Apple that could see the satellite company provide services directly to Apple iPhones. And Iridium, a satellite operator based in Virginia, recently announced that it "entered into a development agreement to enable Iridium's technology in smartphones." And EchoStar continues to hint of interest in working with Dish Network on hybrid satellite-terrestrial services.

Apple is scheduled to unveil its next Phone next month, and it could potentially announce a phone-to-satellite service with Globalstar then.

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— Mike Dano, Editorial Director, 5G & Mobile Strategies, Light Reading | @mikeddano